C++ Gotchas: Avoiding Common Problems in Coding and Design

Chapter 9. Hierarchy Design

Hierarchy design is hard. Class hierarchies must be flexible enough to allow reasonable extension but concrete enough to actually state a design. They must be as simple as possible while still representing an effective abstraction of the problem domain. Unlike the design of most other program components, class hierarchies will be extended and modified long after their initial developers have designed, compiled, and distributed them. The designer of a class hierarchy must, therefore, also determine the extent and kind of customization its users should be permitted and design accordingly.

Hierarchy design comes down to balancing the various forces on a design to achieve an optimal solution, but, like an analogous problem ...